1. Field of the Invention
The invention relates to a receiver for receiving an RF signal modulated with frames of time-interleaved data bits, said receiver comprising:
means for retrieving the frames of time-interleaved data bits from the RF signal, and for generating metrics in response to retrieved data bits, a metric comprising a retrieved data bit and a number of reliability bits associated with each retrieved data bit and indicating the reliability of said data bit, PA1 de-interleaving means comprising metrics storage means for storing the metrics, a storage capacity of the storage means being smaller than a total number of metrics per frame. PA1 either applications requiring a limited storage capacity at a high quality, PA1 or applications which occupy most or all of the data capacity, of a frame and consequently require a large storage capacity at a reduced quality.
The invention also relates to a de-interleaving arrangement for de-interleaving a digital signal arranged in frames, a frame comprising metrics, including a data bit and a number of reliability bits associated with each data bit indicating the reliability of said data bit, the de-interleaving arrangement comprising metrics storage means for storing the metrics, a storage capacity of the storage means being smaller than a total number of metrics per frame.
2. Description of the Related Art
The invention further relates to such a method. The receiver, the de-interleaving arrangement and the method according to the preamble are known from PCT International Application No. WO 96/20536, corresponding to U.S. patent application Ser. No. 08/576,544, filed Dec. 21, 1995. The known receiver comprises means for retrieving the data from the received RF signal, and adds to this, data reliability bits for indicating the reliability of the received data bits. The resulting bits are then de-interleaved, using storage memory means for temporarily storing these bits for de-interleaving purposes. A limited storage capacity is sufficient for de-interleaving a high quality audio application and sometimes a second application as well, as the data of such an audio application takes up only a part of the data capacity of a frame. Therefore a low-cost storage means (also called de-interleaving memory) is dimensioned such that only these applications can be processed. This effectively restricts the use of such a de-interleaving memory to applications not exceeding the available storage capacity of the de-interleaving memory. An application like digital video, using a major part of the total data capacity of a frame, can not be processed by the known receiver.